Hey folks. I was watching video from Transworld and I was wondering if someone would give a "informationally challenged new guy" the basic idea how those violent shaking animatronics work? Is it all multi action pnuematics or are there servos also? I appreciate any info or links. This seems to be a very helpful group.

However 90% of the animatronics you would see at the Transworld Haunt Show in St. Louis would have been pneumatic. A few such as the Skulltronix product line are servos, and a few like the Distrotions rocking granny are a motor.

They are all pnumatic. But since your building it and you know your strengths and capabilities build it the way you like. That way you have a product that appeals to you and no one feels "ripped off"
I much prefer motors or servos in my props but Im also not into the violent thrashing ones.
Allen H

I appreciate the feedback. It looks from these posts that You contribute alot!! Is there a particular reason you use servos? Do you have any link suggestions or books I should pick up. I am going to Transworld if you have any suggestions there. Thanks again!!

Pneumatic use is going to provide you with the force and lengths of movement. Servos uses are good for precise actions such as the up and down movement of an eyelid on an audio animatronic in a very confined space.

"Is there a particular reason you use servos? Do you have any link suggestions or books I should pick up. I am going to Transworld if you have any suggestions there. Thanks again!!"
I am just getting into servos myself and it has been very difficult finding info. Two companies jump out as very helpful. www.EFX-tek.com (join their forums, super helpful!)www.Servocity.com
I prefer electric motors and servos because I go for more subtle animatronics. Like five or six rats on a corpse that turn and look at the guests as they pass by the bodies the rats are munching on. Making a caged body swing slightly to add movement to a set. The rocking granny (by distortions) is a great example of a simple electric animatronic. I like the subtle movements that distract the patrons and then allow the actor to be the force of violence and chaos in the room.
I suppose that I should say that the subtle things that I do are more like a part of the environment as opposed to the big pneumatics that are often the focus of the room. To me they always seem to never quite fit into their surroundings. I also never find them to be believable and I try very hard to not snap the patrons out of the world I attempt to create.
All approaches have their place for sure, I just like a certain style of show. Its a style preference. If you want violence then go pneumatic, If you want atmosphere or lighter scares go servo.
I am doing a seminar on stilts and costumes that break the form of the actors body at transworld. Its a speed seminar so its on WED.
I also make myself very accessible at the show (and the Ren Grand bar afterwards) so please feel free to come and talk to me (that goes for everyone).
I do contribute alot I want to help others be good at something I am passionate about. Im one of the rare full time haunters and helping others keeps me from getting burned out.
Allen H

That all makes sense and I agree with your concept on being subtle. Maybe some day I will get a chance to visit your attraction and in the meantime I will plan on introducing myself at Trans. and buy you a beverage for your help.

Allen, that was insightful stuff. I hadn't thought using servos that way - like the feasting rats you described. I dunno if you built that, but I bet it would be a very cool atmospheric prop. I agree with you that if a prop breaks a patron out of the world you've created, it has failed.

As for a shaking body, a design I played with (but never built - so anyone can be the first) is this: Start with a big induction motor running off of grid power (120V AC). Have this motor driving a camshaft, after gearbox reduction. That main camshaft could be geared to other camshafts to spread out the motion.

A camshaft has components like these

Now for every part of the body you want to shake, just add a cam and spring-loaded cam follower. You could let gravity replace the spring, but to get a violent action, I'd suggest the spring.

This setup has been used a lot for toy automata but I bet it could be applied to achieve this effect, too.

cam-driven toy automaton

Advantages: precise control over shaking motion. Very simple to add more points of motion (just replicate the cam mechanism) - imagine a body shaking at 15 different points, driven by a single motor.